Activate or Wait – 001

Anteroseptal STEMI

• Previously seen ST elevation in leads V1-3 is now significantly more pronounced, meeting traditional “STEMI” criteria
• Inferolateral ST depression is more prominent

ST elevation in aVR adds little diagnostic value here. It is most likely a reflection of diffuse subendocardial ischaemia, due to a combination of evolving infarction, tachycardia +/- hypotension (we are not given a blood pressure). Although infarction of the basal septum can cause ST elevation in aVR, we already suspect the above changes are secondary to left anterior descending artery (LAD) occlusion.

Take a deep dive into the misnomer of ST elevation in aVR.

• Prominent ST elevation in leads V1-3
• Reciprocal inferolateral ST depression in leads II, aVF, V5-6
• Asymmetric, peaked anterior T waves in V2-3 are quite atypical for occlusion and resemble a benign early repolarisation pattern. However, we should never diagnose early repolarisation when ST depression is present in any lead other than aVR
• Sinus tachycardia is likely secondary to pain and ischaemia

This ECG appearance has been recently termed precordial swirl, and is highly specific for
LAD occlusion (see clinical pearls below). The degree of ST elevation often fails to meet
traditional STEMI criteria.

Given proximity to arrival, no activation call was made. The cardiology team met the patient on arrival and a second ECG was performed:

PMcardio’s AI ECG model identified a STEMI/STEMI equivalent.

The explainability feature offers insights into problematic patterns in the respective leads, providing a clear rationale for the diagnosis.

This patient was taken for emergent angiography.

Key Finding:

Findings:

• Left Main Coronary Artery – Normal
• Left Anterior Descending Coronary Artery – Occluded proximally. Type III vessel.
• Left circumflex coronary artery – Large calibre vessel. Co-dominant. Mild irregularities.
• Right coronary artery- Small calibre vessel. Co-dominant. Mild diffuse disease.

Conclusion:

• Single vessel coronary artery disease. Occluded LAD.
• Proceeded to percutaneous coronary intervention to LAD.

Recommendation:

Admit CCU

Dual antiplatelet therapy – aspirin 100mg + ticagrelor 90mg BD for 12 months. Aspirin 100mg daily for life

Ongoing aggressive cardiovascular risk factor management

Smoking cessation

Further reading

• Smith SW. Precordial Swirl – 20 cases of Swirl or Look-Alikes. Dr Smith’s ECG blog
• Buttner R, Burns E. Anterior Myocardial Infarction. LITFL
• Nickson C. STEMI Management. LITFL
• Burns E, Buttner R. T wave. LITFL

Online resources

• Smith SW. Dr Smith’s ECG blog.
• Wiesbauer F, Kühn P. ECG Mastery: Yellow Belt online course. Understand ECG basics. Medmastery
• Wiesbauer F, Kühn P. ECG Mastery: Blue Belt online course: Become an ECG expert. Medmastery
• Kühn P, Houghton A. ECG Mastery: Black Belt Workshop. Advanced ECG interpretation. Medmastery
• Rawshani A. Clinical ECG Interpretation ECG Waves